Effects of Eight Types of Dwarfing Self-Rooted Rootstocks on Scion 'yanfu 3' Growth, Fruit Quality and Botryosphaeria Dothidea Resistance

Dwarfing rootstocks of apples not only improve the growth of the scion but also increase the economic benefits of orchards. In this study, apple rootstock trials using the 'Yanfu 3' cultivar were established to evaluate eight rootstocks for horticultural performance and ring rot (Botryosphaeria dothidea) resistance. The scion variety 'Yanfu 3,' which is a bud sport mutation from 'Fuji,' was grafted onto M9T337, MM106, JM7, B176, B150, B160, B396 and B118 rootstocks. The same cultivation management was used applied for 6 years of apple tree growth. Then, the effects of different rootstocks on fruit quality, fruit yield, tree growth, branch number, proportion of various branches, flower bud number, mineral elements of leaves and incidence of ring rot on the scions were analysed and compared. The results showed that the scion with B118 as the rootstock had the best soluble solids content, and the scions with JM7 and M9T337 as the rootstocks had the highest fruit yield. Among the eight rootstocks, only the rootstock-scion combinations with B396 and B118 had 'undergrowth,' while the fruit tree growth of the B118 rootstock was the most vigorous. The M9T337 rootstock produced the largest number of flower buds and short branches, and the B396 rootstock had the lowest incidence of ring rot. Moreover, the different rootstocks had no effect on the uptake of N, B, Fe and Zn by the scion leaves and had minimal effects on P, K, Ca and Mg. In short, rootstocks have their own unique advantages and can be selected according to cultivation needs.